1. Field of the Invention
This invention generally relates to the treatment of aneurysms and more specifically to a method and apparatus for treating aneurysms.
2. Description of Related Art
Aneurysms, as known, are abnormal dilatations of a vessel caused by weakening of the vessel's wall that can occur anywhere in the body. Most commonly aneurysms occur in cerebral and aortic vessels, and they must be treated to avoid rupture and hemorrhage.
Conventional treatment involves the placement of clips on the aneurysm during a surgical procedure. The clips essentially gather the weakened aneurysmal wall to prevent its exposure in its weakened state to the pressure exerted by and flow dynamics of blood in the vessel. Such surgery involves patient risk and trauma and foreign objects, such as the clips, remain in the patient's body.
U.S. Pat. No. 5,219,355 to Parodi et al. discloses a balloon device for implanting an aortic or aortodiiliac intraluminal prothesis for repairing aneurysms. The device includes a catheter having two inflatable balloons for expanding two stents associated with a tube extending through the vessel internally of and in parallel to the aneurysm. When the prothesis is properly located, the balloons inflate and expand the stents into contact with normal vessel wall portions adjacent the aneurysm to clamp the tube in place. The tube provides a continuous passage through the dilatation and eliminates the application of pressure to the weakened aneurysmal wall. The tube and the stents remain in the patient after the balloons are deflated and withdrawn with the catheter. This balloon device is described for the treatment of aortic aneurysms. It does not appear reasonable to apply this approach to cerebral aneurysms where the vessels are significantly smaller than aortic vessels. Moreover, the apparatus is disclosed for the repair of aneurysms that form in a single passage vessel. In many cases, however, an aneurysm forms at a bifurcation in the vessel system where a single passage may divide into two or more passages. Such apparatus would not appear adapted to the treatment of such aneurysms.
U.S. Pat. No. 4,832,688 to Sagae et al. discloses a multi-lumen catheter for the repair of a ruptured blood vessel. In one embodiment, the catheter carries two axially spaced occlusion balloons and an intermediate clamping balloon that is positioned proximate a tear in a vessel wall. The catheter additionally includes a lumen for injecting a therapeutic agent, such as heparin, between the occlusion balloons. In use, the occlusion balloons inflate to isolate a volume around the rupture in the vessel wall. After heparin is administered, the middle balloon expands to hold the ruptured wall in position until the repair is effected. After some time interval, all the balloons are deflated and the catheter is removed from the patient.
U.S. Pat. No. 5,019,075 to Spears et al. discloses a thermal balloon for heating surrounding tissue, particularly in connection with percutaneous transluminal coronary angioplasty. Heating fuses together fragmented segments of tissue and coagulates blood trapped within dissected planes of the tissue and within fissures created by any wall fractures. This activity prevents the collapse of any flap of material that could cause either abrupt arterial closure or gradual restenosis at the site of the treatment.
Both the Sagae et al. and Spears et al. patents disclose apparatus for use in percutaneous transluminal angioplasty. Neither, however, suggests any use of their respective devices or apparatus in the treatment of aneurysms.